Just picked up a 1Ds MK II. Took a test shot and noticed the upper left corner is very SOFT On my 1D MK II the softness in that corner would go away at f/13 but not on the FF body. Is this something Sigma can fix/calibrate? I really don't have the cash to replace this lens

I'm not sure there's much you can do; lack of sharpness in the corners is the compromise when using this lens with a FF body. Despite its compatibility with 35mm it's "optimised for digital" which to me means crop, the 1.3 factor of the 1D probably being the limit. I read a couple of customer reviews and the gripes when using the lens at 12mm on FF are farily consistent: lack of corner sharpness, vignetting.

Thanks Davi! The strange thing is it's just the upper left corner that is soft. I could understand of all 4 corners were soft but just 1 This photo shows the softness a bit better...

@12mm
f/8
1/320
ISO 400

Quote:

Originally Posted by Davi

I'm not sure there's much you can do; lack of sharpness in the corners is the compromise when using this lens with a FF body. Despite its compatibility with 35mm it's "optimised for digital" which to me means crop, the 1.3 factor of the 1D probably being the limit. I read a couple of customer reviews and the gripes when using the lens at 12mm on FF are farily consistent: lack of corner sharpness, vignetting.

Agreed the top left is particularly soft, but top right also looks a little soft to me - both in the mesh in the corner of the first image, and in the roof detail in the second image. Maybe calibration would help a little, but at the end of the day its midrange glass on a full format camera.

I don't mind the right corner so much. The left is what's really bugging me

Quote:

Originally Posted by Davi

Agreed the top left is particularly soft, but top right also looks a little soft to me - both in the mesh in the corner of the first image, and in the roof detail in the second image. Maybe calibration would help a little, but at the end of the day its midrange glass on a full format camera.